A central component of such a booster clutch device is a so-called torque sensor. The booster clutch device has a pilot clutch and a main clutch. In particular, a motor and a transmission are provided, which are connected or coupled by the booster clutch device. The pilot clutch and the main clutch are connected to each other by the ramp system referred to above. A transmissible torque from the motor to the transmission corresponds to a main clutch contact force. The main clutch contact force corresponds to an axial movement of a contact plate (plates of the main clutch). An axial movement corresponds in turn to a rotation of a ramp around an angle. A transmissible torque therefore corresponds to a rotation of the ramp around an angle. The relationship between torque and angle can be depicted by a ramp torque characteristic.
The torque sensor can be envisioned as a torsion spring device, which is situated in particular between the transmission and the main clutch. If a load alteration now occurs, then the transmitted torque in the drivetrain changes, which in turn changes the tension of the torsion spring device. To avoid jamming of the ramp system under such load alterations, the spring characteristic of the torsion spring device must be adjusted accordingly, and must correspond as closely as possible to the ramp torque characteristic. This makes it possible to ensure than when the load changes, the changing torque to be transmitted can then be transmitted reliably by adjusting the contact force of the main clutch. A torque sensor inserted into a drivetrain makes it possible for a rotation to be caused when such a variation of torques occurs under a load alteration, where the torsion spring angle that occurs corresponds to a torque. If the torsional spring stiffness is too low, then the torsional spring device can rotate too severely, so that one of the ramps assumes a position in which the contact force is too low compared to the torque to be transmitted. But if the torsional spring stiffness is greater than the ramp torque stiffness, the ramp may remain jammed.
Such clutch devices or booster clutches having torque sensors are known, but they are highly complex, and are correspondingly demanding in terms of manufacture and installation. Furthermore, these clutch devices have numerous individual parts, each of which requires expensive processing in order to guarantee the functioning of the clutch device.